The survey was conducted by Brandon Rottinghaus, a professor of political science at the University of Houston, and Justin S. Vaughn, an associate professor of political science and director of the Center for Idaho History and Politics at Boise State University.

Their op-ed, was posted Monday in the Times, showed Barack Obama faring much better than Trump. Obama shot into the top 10, up from 18th when a previous survey was conducted in 2014.

The authors said the four years since the previous survey had other changes in rankings, with James Buchanan, who was at the helm as the United States careened into civil war, benefiting from the Trump era. Buchanan was dislodged from his position as our nation’s worst president by Trump.

The biggest declines were for Bill Clinton, who slipped eight spots to No. 13, and Andrew Jackson, who dropped from No. 9 to 15.

The authors say Trump has, at least, the most room for improvement when another survey is taken.

"Trump’s initial rating places him in an ignominious category, but dozens of presidents have had slow starts and have course corrected to improve their public esteem,'' Rottinghaus and Vaughn wrote. "Beyond his reputation or ranking, Donald Trump’s very presidency may alter perceptions of presidential legacies as his unique approach to the office continues to surprise.''